Designed to meet an Air Ministry specification for a high-speed, high-altitude, long-range nuclear bomber, the Avro Vulcan was first flown on August 30, 1952. Though revolutionary, the Vulcan's original delta wing tailless design was an unknown quantity. The first prototype crashed in the fall of 1949 and the early straight leading edge design was later modified to kink towards the wingtip, giving the service aircraft superior flying characteristics. Carrying Britain's first nuclear weapon (the Blue Danube), the Vulcan's original role was nuclear deterrence, but it was later modified for air-to-air refueling missions and maritime radar reconnaissance.